Re: [PATCH v4] irqchip/irq-mst: Support polarity configuration

2021-04-07 Thread Marc Zyngier
On Mon, 15 Mar 2021 21:18:48 +0800, Mark-PK Tsai wrote:
> Support irq polarity configuration and save and restore the config
> when system suspend and resume.

Applied to irq/irqchip-next, thanks!

[1/1] irqchip/irq-mst: Support polarity configuration
  commit: ea4aeaa5c88906eb3ca3d7d3d17a45605d2dd0de

Cheers,

M.
-- 
Without deviation from the norm, progress is not possible.




Re: [PATCH v4] irqchip/irq-mst: Support polarity configuration

2021-04-07 Thread Marc Zyngier
On Mon, 15 Mar 2021 13:18:48 +,
Mark-PK Tsai  wrote:
> 
> Support irq polarity configuration and save and restore the config
> when system suspend and resume.
> 
> Signed-off-by: Mark-PK Tsai 
> ---
>  drivers/irqchip/irq-mst-intc.c | 94 --
>  1 file changed, 91 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/irqchip/irq-mst-intc.c b/drivers/irqchip/irq-mst-intc.c
> index 143657b0cf28..a2ab3f837b96 100644
> --- a/drivers/irqchip/irq-mst-intc.c
> +++ b/drivers/irqchip/irq-mst-intc.c
> @@ -13,15 +13,27 @@
>  #include 
>  #include 
>  #include 
> +#include 
>  
> -#define INTC_MASK0x0
> -#define INTC_EOI 0x20
> +#define MST_INTC_MAX_IRQS64
> +
> +#define INTC_MASK0x0
> +#define INTC_REV_POLARITY0x10
> +#define INTC_EOI 0x20
> +
> +#ifdef CONFIG_PM_SLEEP
> +static LIST_HEAD(mst_intc_list);
> +#endif
>  
>  struct mst_intc_chip_data {
>   raw_spinlock_t  lock;
>   unsigned intirq_start, nr_irqs;
>   void __iomem*base;
>   boolno_eoi;
> +#ifdef CONFIG_PM_SLEEP
> + struct list_head entry;
> + u16 saved_polarity_conf[DIV_ROUND_UP(MST_INTC_MAX_IRQS, 16)];
> +#endif
>  };
>  
>  static void mst_set_irq(struct irq_data *d, u32 offset)
> @@ -78,6 +90,20 @@ static void mst_intc_eoi_irq(struct irq_data *d)
>   irq_chip_eoi_parent(d);
>  }
>  
> +static int mst_irq_chip_set_type(struct irq_data *data, unsigned int type)
> +{
> + if (type != IRQ_TYPE_EDGE_RISING && type != IRQ_TYPE_EDGE_FALLING &&
> + type != IRQ_TYPE_LEVEL_HIGH && type != IRQ_TYPE_LEVEL_LOW)
> + return -EINVAL;

All of this amounts to checking for IRQ_TYPE_{NONE,EDGE_BOTH}. Maybe
that's a better option.

> +
> + if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_EDGE_FALLING)
> + mst_set_irq(data, INTC_REV_POLARITY);

What happens if the interrupt was set to LEVEL_LOW, then switched to
LEVEL_HIGH? You end up with a stuck reversed polarity.

> +
> + type = IRQ_TYPE_LEVEL_HIGH;
> +
> + return irq_chip_set_type_parent(data, type);

I'm going to fix this as below. Shout if you disagree.

Thanks,

M.

diff --git a/drivers/irqchip/irq-mst-intc.c b/drivers/irqchip/irq-mst-intc.c
index a2ab3f837b96..f6133ae28155 100644
--- a/drivers/irqchip/irq-mst-intc.c
+++ b/drivers/irqchip/irq-mst-intc.c
@@ -92,16 +92,20 @@ static void mst_intc_eoi_irq(struct irq_data *d)
 
 static int mst_irq_chip_set_type(struct irq_data *data, unsigned int type)
 {
-   if (type != IRQ_TYPE_EDGE_RISING && type != IRQ_TYPE_EDGE_FALLING &&
-   type != IRQ_TYPE_LEVEL_HIGH && type != IRQ_TYPE_LEVEL_LOW)
-   return -EINVAL;
-
-   if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_EDGE_FALLING)
+   switch (type) {
+   case IRQ_TYPE_LEVEL_LOW:
+   case IRQ_TYPE_EDGE_FALLING:
mst_set_irq(data, INTC_REV_POLARITY);
+   break;
+   case IRQ_TYPE_LEVEL_HIGH:
+   case IRQ_TYPE_EDGE_RISING:
+   mst_clear_irq(data, INTC_REV_POLARITY);
+   break;
+   default:
+   return -EINVAL;
+   }
 
-   type = IRQ_TYPE_LEVEL_HIGH;
-
-   return irq_chip_set_type_parent(data, type);
+   return irq_chip_set_type_parent(data, IRQ_TYPE_LEVEL_HIGH);
 }
 
 static struct irq_chip mst_intc_chip = {

-- 
Without deviation from the norm, progress is not possible.


[PATCH v4] irqchip/irq-mst: Support polarity configuration

2021-03-15 Thread Mark-PK Tsai
Support irq polarity configuration and save and restore the config
when system suspend and resume.

Signed-off-by: Mark-PK Tsai 
---
 drivers/irqchip/irq-mst-intc.c | 94 --
 1 file changed, 91 insertions(+), 3 deletions(-)

diff --git a/drivers/irqchip/irq-mst-intc.c b/drivers/irqchip/irq-mst-intc.c
index 143657b0cf28..a2ab3f837b96 100644
--- a/drivers/irqchip/irq-mst-intc.c
+++ b/drivers/irqchip/irq-mst-intc.c
@@ -13,15 +13,27 @@
 #include 
 #include 
 #include 
+#include 
 
-#define INTC_MASK  0x0
-#define INTC_EOI   0x20
+#define MST_INTC_MAX_IRQS  64
+
+#define INTC_MASK  0x0
+#define INTC_REV_POLARITY  0x10
+#define INTC_EOI   0x20
+
+#ifdef CONFIG_PM_SLEEP
+static LIST_HEAD(mst_intc_list);
+#endif
 
 struct mst_intc_chip_data {
raw_spinlock_t  lock;
unsigned intirq_start, nr_irqs;
void __iomem*base;
boolno_eoi;
+#ifdef CONFIG_PM_SLEEP
+   struct list_head entry;
+   u16 saved_polarity_conf[DIV_ROUND_UP(MST_INTC_MAX_IRQS, 16)];
+#endif
 };
 
 static void mst_set_irq(struct irq_data *d, u32 offset)
@@ -78,6 +90,20 @@ static void mst_intc_eoi_irq(struct irq_data *d)
irq_chip_eoi_parent(d);
 }
 
+static int mst_irq_chip_set_type(struct irq_data *data, unsigned int type)
+{
+   if (type != IRQ_TYPE_EDGE_RISING && type != IRQ_TYPE_EDGE_FALLING &&
+   type != IRQ_TYPE_LEVEL_HIGH && type != IRQ_TYPE_LEVEL_LOW)
+   return -EINVAL;
+
+   if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_EDGE_FALLING)
+   mst_set_irq(data, INTC_REV_POLARITY);
+
+   type = IRQ_TYPE_LEVEL_HIGH;
+
+   return irq_chip_set_type_parent(data, type);
+}
+
 static struct irq_chip mst_intc_chip = {
.name   = "mst-intc",
.irq_mask   = mst_intc_mask_irq,
@@ -87,13 +113,62 @@ static struct irq_chip mst_intc_chip = {
.irq_set_irqchip_state  = irq_chip_set_parent_state,
.irq_set_affinity   = irq_chip_set_affinity_parent,
.irq_set_vcpu_affinity  = irq_chip_set_vcpu_affinity_parent,
-   .irq_set_type   = irq_chip_set_type_parent,
+   .irq_set_type   = mst_irq_chip_set_type,
.irq_retrigger  = irq_chip_retrigger_hierarchy,
.flags  = IRQCHIP_SET_TYPE_MASKED |
  IRQCHIP_SKIP_SET_WAKE |
  IRQCHIP_MASK_ON_SUSPEND,
 };
 
+#ifdef CONFIG_PM_SLEEP
+static void mst_intc_polarity_save(struct mst_intc_chip_data *cd)
+{
+   int i;
+   void __iomem *addr = cd->base + INTC_REV_POLARITY;
+
+   for (i = 0; i < DIV_ROUND_UP(cd->nr_irqs, 16); i++)
+   cd->saved_polarity_conf[i] = readw_relaxed(addr + i * 4);
+}
+
+static void mst_intc_polarity_restore(struct mst_intc_chip_data *cd)
+{
+   int i;
+   void __iomem *addr = cd->base + INTC_REV_POLARITY;
+
+   for (i = 0; i < DIV_ROUND_UP(cd->nr_irqs, 16); i++)
+   writew_relaxed(cd->saved_polarity_conf[i], addr + i * 4);
+}
+
+static void mst_irq_resume(void)
+{
+   struct mst_intc_chip_data *cd;
+
+   list_for_each_entry(cd, _intc_list, entry)
+   mst_intc_polarity_restore(cd);
+}
+
+static int mst_irq_suspend(void)
+{
+   struct mst_intc_chip_data *cd;
+
+   list_for_each_entry(cd, _intc_list, entry)
+   mst_intc_polarity_save(cd);
+   return 0;
+}
+
+static struct syscore_ops mst_irq_syscore_ops = {
+   .suspend= mst_irq_suspend,
+   .resume = mst_irq_resume,
+};
+
+static int __init mst_irq_pm_init(void)
+{
+   register_syscore_ops(_irq_syscore_ops);
+   return 0;
+}
+late_initcall(mst_irq_pm_init);
+#endif
+
 static int mst_intc_domain_translate(struct irq_domain *d,
 struct irq_fwspec *fwspec,
 unsigned long *hwirq,
@@ -145,6 +220,15 @@ static int mst_intc_domain_alloc(struct irq_domain 
*domain, unsigned int virq,
parent_fwspec = *fwspec;
parent_fwspec.fwnode = domain->parent->fwnode;
parent_fwspec.param[1] = cd->irq_start + hwirq;
+
+   /*
+* mst-intc latch the interrupt request if it's edge triggered,
+* so the output signal to parent GIC is always level sensitive.
+* And if the irq signal is active low, configure it to active high
+* to meet GIC SPI spec in mst_irq_chip_set_type via REV_POLARITY bit.
+*/
+   parent_fwspec.param[2] = IRQ_TYPE_LEVEL_HIGH;
+
return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, 
_fwspec);
 }
 
@@ -193,6 +277,10 @@ static int __init mst_intc_of_init(struct device_node *dn,
return -ENOMEM;
}
 
+#ifdef CONFIG_PM_SLEEP
+   INIT_LIST_HEAD(>entry);
+   list_add_tail(>entry, _intc_list);
+#endif
return 0;
 }
 
-- 
2.18.0